Presently, microtiter plate readers with separate filter slides for excitation filters and emission filters are known. Apparatuses for irradiating samples which can be characterized by light penetrating the samples (transmission), the light reflected by the samples (reflection), light initiated on or in the sample (fluorescence) or light emitted by the samples themselves (luminescence) have been known as microscopes, spectrophotometers, fluorometers and the like. The light that penetrates the sample during the irradiation or is reflected by the same or the fluorescence initiated on or in the sample will be designated below as “light originating from the sample” and will be measured for example by one or several photodetectors. The use of different optical filters for influencing light rays with which the samples are radiated or light that is transmitted through the same (so-called excitation filters) is known. Similarly, emission filters are known which influence the light emitted by the samples. Furthermore, dichroic mirrors are known which reflect certain wavelengths and passes other wavelengths.
Since optical components, such as filters or mirrors, may be exchanged by a user of the apparatus, the components need to be identified. Identification labels may be attached to the components to provide information of the components. However, automatic identification of components is desired. Such automatic identification may be utilized using bar codes, for example. Using bar codes the apparatus may identify the optical components. However, even such solution does not provide any further information on the optical component characteristics than what is inserted to a database of the system. Bar codes are also troublesome for user's own components that do not support similar bar codes as the apparatus manufacturer. Thus it is desired to have an apparatus and a method for automatically identifying an optical component of the apparatus and also enables a reliable identification of user's own optical components.